This is a reStructuredText version of https://docs.google.com/a/google.com/document/d/1DmLVyZqqwWSZ0is91lipTm4xsfjInSba2KBOOxatYhg/edit?usp=sharing which for technical reasons is only visible to @google.com accounts.

Also update README.rst to be more accurate.

BUG= none
R=jfb@chromium.org, jpp@chromium.org, jvoung@chromium.org

Review URL: https://codereview.chromium.org/1309073003.